Method of manufacturing baked beverage in container

ABSTRACT

A method of manufacturing a high quality beverage capable of providing beverage by an extraction after roasting the material thereof and filling beverage of a roast material in a container and sealing the container. The method comprises a step for roasting the material in a sterile atmosphere, and extracting the roast material or preparing a suspension of the roast material with sterilized water, wherein sterilized inert gas atmosphere is used as the sterile atmosphere in at least a part of the step, whereby since both the deterioration of quality due to oxidation and the deterioration of quality by heating can be prevented, the high quality beverage of the roast material can be manufactured.

TECHNICAL FIELD

This invention relates to a method for manufacturing beverage of a roastmaterial in a container by which a material of beverage such as coffeebeverage, cocoa beverage and roast barley beverage is roasted andbeverage is obtained by extraction or addition of water and then theobtained beverage is filled in a container which is then sealed.

BACKGROUND ART

Various methods have in the past been used and proposed for preventingoxidization of beverage in a container. As to prevention of oxidizationof beverage of a roast material, Japanese Patent Application Laid-openPublication Sho 51-57863 proposes, for example, conducting all processesof extraction of beverage from coffee powder, filtering and filling ofthe beverage in a container and sealing of the container under pressureof inert gas. Japanese Patent Application Laid-open Publication Hei9-262055 discloses a method for manufacturing coffee contained in acontainer according to which an empty container is kept in anoxygen-free state in its inside and coffee produced in the presence ofinert gas or in an oxygen-free state is filled in this container,whereby all processes from raw material to filling and sealing areconducted in an oxygen-free state.

These prior art method for preventing oxidization of beverage of a roastmaterial in a container in which all processes from extraction ofbeverage to filling of the beverage in a container and sealing of thecontainer in an oxygen-free state are effective for preventingdeterioration of quality of the beverage. In all of these methods,however, beverage must be subjected to sterilization by heating afterfilling of the beverage in a container and sealing of the container byretort treatment under a temperature from 120° C. to 125° C. for 30minutes to 40 minutes with resulting disadvantage that this heatingdeteriorates quality of the beverage and, in the case of coffee, forexample, fragrance and taste of just roasted coffee are lost.

DISCLOSURE OF THE INVENTION

Repeated studies and experiments made by the inventors of the presentinvention have resulted in the finding, which has led to the presentinvention, that, in manufacturing of coffee beverage, cocoa beverage,barley beverage etc., coffee beans, cocoa beans, barley grains etc.which are raw materials of beverage are heated to a temperature about200° C. in the roasting process and, at this time, these materials arebrought into a sterile state and, by conducting processes after roastingin sterile atmosphere, conducting extraction of the roast material orpreparation of a suspension of the roasted material with sterile waterand using, at least in a part (preferably all) of these processes,sterile inert gas atmosphere as the sterile atmosphere, deterioration ofquality of the beverage due to oxidization can be prevented and, sinceheating such as retort treatment for sterilizing the beverage is notneeded in any process after roasting to completion of the beverage ofthe roast material in a container, deterioration of quality of thebeverage due to heating can also be prevented whereby beverage of aroast material of a high quality can be produced.

For achieving the object of the present invention, a method formanufacturing beverage of a roast material in a container ischaracterized in that processes from roasting of a material to fillingof beverage in a container and sealing of the container are conducted insterile atmosphere, extraction of the roast material or preparation of asuspension of the roast material is conducted with sterile water and, atleast in a part of said processes, sterile inert gas atmosphere is usedas the sterile atmosphere.

In one aspect of the invention, the method for manufacturing beverage ofa roast material in a container is characterized in that extraction ofthe roast material or preparation of a suspension of the roast materialis conducted with deoxidized sterile water.

According to the present invention, the material is brought into asterile state by roasing and, by conducting processes after roasting insterile atmosphere, conducting extraction of the roast material orpreparation of a suspension of the roasted material with sterile waterand using, at least in a part of these processes, sterile inert gasatmosphere as the sterile atmosphere, deterioration of quality of thebeverage due to oxidization and heating can be prevented and beverage ofa roast material of a high quality can thereby be produced.

Moreover, by conducting extraction of the roast material or preparationof a suspension of the roast material with deoxidized sterile water,oxidization of the beverage can further be prevented.

BRIEF DESCRIPTION OF THE DRAWING

FIG. 1 is a flow chart showing processes of the method for manufacturingbeverage of a roast material in a container according to the invention.

DESCRIPTION OF PREFERRED EMBODIMENTS OF THE INVENTION

The present invention can be applied to a method for manufacturingbeverage in a container according to which materials such as coffeebeans, cocoa beans and barley grains for beverages such as coffeebeverage, cocoa beverage and roast barley beverage are roasted andbeverage is extracted from the roast material or a suspension of theroast material is prepared. As to coffee beverage, the present inventioncan be applied not only to black coffee beverage but also to milk coffeebeverage by using UHT milk or long-life milk and also to sweetenedcoffee beverage by using sterilized sweetener such as syrup which hasbeen sterilized by filtering or the like method.

Conditions for roasting differ depending upon a material used. In thecase of coffee beans, roasting is made by heating coffee beans at atemperature within a range from 200° C. to 210° C. for ten minutes tofifteen minutes. This roasting by far exceeds heating conditions ofgeneral dry heating sterilization and, as a result, the roast coffeebeans are completely sterilized. The same is the case with the otherroast materials.

The roast material is conveyed to a next process aseptically whilemaintaining the sterilized state. In some case, the roast material maybe conveyed to a next process after being packed in a sterile state to asterilized container and the container may be opened in a sterile statein the next process.

Processes for manufacturing the beverage in a container after roastingsuch as crushing of the roast material are all conducted in a sterilestate. More specifically, respective processes using apparatuses such asa crusher which can treat the material under sterile conditions and anextractor which can extract beverage from the roast material understerile conditions are all conducted in sterile atmosphere such as acleanroom. In a process for cooling the material after roasting, airwhich has been sterilized by, for example, filtering through a doubleHEPA filter is used as cold wind for cooling. Apparatuses such as acrusher and an extractor are treated for necessary initial sterilizationby applying known methods such as heating (dry heat sterilization or wetheat sterilization) and gas sterilization.

By using such initially sterilized apparatuses, liquid for beverage isprepared by extracting the roast material in a sterile state withsterile water or a suspension of the roast material is prepared byadding sterile water to the roast material. The sterile water used forextraction or preparation of a suspension is sterilized by suitablemeans such as heating by a heat exchanger, sterilization by aultraviolet ray water sterilizer and filtration. Additional materialssuch as sugar, milk and spices to be added to the beverage are alsosterilized by suitable means such as heating and filtration.

The liquid for beverage obtained by extracting the roast material withsterile water or by adding water to the roast material in sterileatmosphere is filled in a sterilized container such as a PET bottle,metal can, pouch, paper cup and plastic cup under sterile conditions andthe container is sealed to provide a final beverage product. As anapparatus for achieving filling and sealing in a sterile state, ageneral aseptic container filling apparatus can be used.

For preventing oxidization of the roast material and liquid for beverageby air in the process after roasting, sterilized inert gas is introducedas sterile atmosphere to respective apparatuses for treating the roastmaterial and liquid for beverage to substitute air and form sterileinert gas atmosphere. Since nitrogen gas is a representative inert gaswhich is commercially available easily, the following description willbe made as using nitrogen gas.

Nitrogen gas can be sterilized by using, for example, a cartridge filterwhich has been sterilized with steam. For preventing oxidization, it ispreferable to form sterile nitrogen gas atmosphere as sterile atmospherein all processes after roasting. In a case where, depending upon thetype of the roast material, complete prevention of oxidization is notnecessary, use of the sterile nitrogen gas may be omitted in part of theprocesses after roasting and sterile atmosphere may be formed by sterileair.

Substitution by nitrogen gas is not performed in the roasting processbecause if roasting was made in the nitrogen gas atmosphere, taste andfragrance of the roast material would unfavourably change from theoriginal taste and fragrance. In the cooling process, as describedpreviously, sterile nitrogen gas is not used but cold wind of sterilizedair is used. This is because the surface area of roast material such ascoffee beans is so small that a significant oxidization preventioneffect by substitution by nitrogen gas cannot be achieved.

Water used for extracting the roast material, preparing a suspension anddiluting liquid for beverage is sterilized before using as describedabove. Before sterilization, it is preferable to reduce dissolved oxygenin the water for prevention of oxidization by using an apparatus forproducing deoxidized water. It is also preferable to fill sterilenitrogen gas in head space of all pipes through which water passes andhead space of all tanks in which dilution and mixing are conducted.

In filling liquid for beverage in a container, it is preferable to fillspace between a filling nozzle and the container and the inside space ofthe container with sterilized nitrogen gas.

The process for manufacturing coffee beverage in a container comprisesmainly steps of roasting coffee beans, chaff removing, cooling,crushing, extraction of liquid for beverage from powder, dilution of theliquid for beverage, filling of the liquid for beverage in a containerand sealing of the container. It is preferable to perform all thesesteps except for roasting, chaff removing and cooling in sterilenitrogen gas atmosphere.

In the case of cocoa beverage in a container, the process is differentfrom the coffee beverage in that roast cocoa beans are not extractedafter crushing but a suspension of cocoa is prepared by adding water. Inthe same manner as in the case of coffee beverage, however, it ispreferable to perform all steps except for roasting, chaff removing andcooling in sterile nitrogen gas atmosphere.

In the case of roast barley beverage in a container, the process isdifferent from the coffee beverage in that roast barley grains areextracted without being crushed. In the same manner as in the case ofcoffee beverage, however, it is preferable to perform all steps exceptfor roasting and cooling in sterile nitrogen gas atmosphere.

EXAMPLE

As a typical example of beverage of roast material, an example of themethod for manufacturing coffee beverage in a container will now bedescribed.

Outline of the Process

The process for manufacturing coffee beverage in a container comprisesmainly, as shown in the chart of FIG. 1, roasting of green coffee beans,chaff removing, cooling, crushing, extraction from powder, dilution ofextracted liquid, filling and sealing. As heated water used inextraction and dilution, water which was sterilized by subjecting purewater to ion exchange and sterilization was used. As cold wind used inthe cooling process, air which was sterilized by filtration through adouble HEPA filter was used. All processes from crushing and extractionto sealing were performed in sterilized nitrogen gas atmosphere. As thenitrogen gas for forming this atmosphere, nitrogen gas which wassterilized through a cartridge filter sterilized with steam was used.

Forming of Sterile, Low Oxygen Concentration Atmosphere

Nitrogen gas which was sterilized through a cartridge filter sterilizedwith steam was introduced into a crushing apparatus for preventingoxidization of beans or powder under crushing. The roasted andchaff-removed coffee beans were treated from the crushing process in alow oxygen concentration environment produced by substitution of air bysterile nitrogen gas. Air in space between particles of coffee powderintroduced into an extractor was already substituted by nitrogen gas.Before the powder was put in the extractor, a step of discharging airwith sterile nitrogen gas when the extractor column was empty wasinserted. Water used for extraction which was already sterilized by aheat exchanger or a ultraviolet ray water sterilizer was sterilized in aclosed environment for maintaining a sterile state. For this purpose,the water was heated for sterilization at a temperature exceeding 130°C. but dissolved oxygen was not removed by this heating. Therefore, asthe water for extraction, water in which concentration of dissolvedoxygen was reduced by a deoxidized water producing apparatus was usedand the desired low oxygen concentration in the extracted liquid wasthereby realized. Head space of all pipes through which water passes andhead space of all tanks in which dilution and mixing are conducted wasfilled with sterile nitrogen gas. In the present example, a container inthe shape of a plastic cup was used and air in the space between thefilling nozzle and the cup and the inside space of the cup waspreviously substituted by sterile nitrogen gas.

Initial Sterilization

Before starting manufacturing of the coffee beverage in a container,initial sterilization was conducted for respective apparatuses fromroasting to filling of the liquid in the container and also conveyorsbetween the respective apparatuses. The initial sterilization was madeat 200° C. for 15 minutes in the case of dry heating with gas flame (forchaff removing and cooling) and at 125° C. for 10 minutes in the case ofsteam sterilization (for crushing, extraction and dilution).Sterilization with a sterilizer (for filling and sealing) was alsoconducted by using successive scattering or successive wiping off ofsodium hypochlorite and 70% ethanol. In this manner, the initial sterilestate from the outlet of the roaster to the filling and sealingapparatus was secured. During operation, supply of gas or water wasprohibited except that cold wind was supplied through a double HEPAfilter in the cooling process after roasting, and sterile nitrogen gaswas supplied through a sterilized filter and heated water sterilized bya heat exchanger was supplied to the passing channel of coffee beans andextracted liquid.

Manufacture of Coffee Beverage

After forming the initially sterilized low oxygen concentrationenvironment, 18 kg of green coffee beans were supplied to a continuousroaster at a rate of 300 g per minute. Average dwelling time of thegreen beans in the roasting zone was about 10 minutes. During thedwelling time, the roasting temperature was changed from 165° C. to 210°C. and the green beans thereby became brown. Survival rate of bacteriaon the coffee beans after roasting was measured and it was less than 1per 1 kg, that is, survived bacteria were substantially undetectableand, therefore, the roast beans were considered to be sterilized. Thebeans then were crushed by a crusher with the interval of the roll millbeing set at 0.2 mm. The extractor was composed of six extractingcolumns and four extracting columns among them were used for receivingabout 3.7 kg of powder for each extracting column and extracting liquidin about 12 minutes. The extracting operation was repeated four timesand extracted liquid totaling 250 liter was obtained. Extractingefficiency at this time was 24%. The extracted liquid was transferred toa buffer tank of a filler and filled in plastic cups made of polyesterand having capacity of 240 cc by 200 ml per cup. The cups were thensealed. Oxygen concentration in the head space of each cup was 1.4%.

Tasting after Storing

The coffee beverage in a cup thus produced was stored for two weeks atroom temperature and then the cup was opened and the beverage wastasted. The coffee beverage maintained fragrance and taste of coffeejust after being roasted.

COMPARATIVE EXAMPLES

(1) Sample Made by a General Manufacturing Method

Extracted liquid of coffee was produced according to a general methodfor manufacturing coffee beverage without performing substitution bynitrogen gas. Since extraction was not made in a sterile state, initialsterilization of the extractor was omitted. Since, in the case of coffeebeverage in a plastic cup, means for sterilizing liquid to be filled isa heat exchanger, extracted liquid was sterilized before filling byheating the extracted liquid at 145° C. for 5 seconds by a heatexchanger. A cup and a lid which were sterilized with hydrogen peroxidewere used as the container. In this case, a pH adjusting agent such assodium bicarbonate which was commonly used in the industry was not used.

(2) Sample Made by Low Oxygen Concentration Method

This method was different from the general manufacturing method in thatoxygen free water was used as extracting water, air in the head space ofa filling tank storing extracted liquid was substituted by nitrogen gasand, immediately before sealing, air in the head space of a plastic cupwas substituted by nitrogen gas. Oxygen concentration immediately aftersealing was 1.4%.

(3) Sample Made by Aseptic Method

In this method, processes from roasting to sealing were performed in asterile environment. As a gas for realizing the sterile environment, airwhich was sterilized through a filter was used. Therefore, sterilizationby a heat exchanger was omitted. Substitution of air with nitrogen gaswas conducted only for the head space immediately before sealing.

Result of Organoleptic Test

The sample of the Example of the present invention and the three samplesof the Comparative Examples, totaling four samples, were stored forfifteen days at 25° C. Then, these samples were evaluated by a panelconsisting of five experts who were well acquainted with evaluation ofcoffee. Results of the evaluation are shown in the following Table 1:TABLE 1 Organoleptic Test Manufacturing Total point method fragranceTaste (full marks: 5) General method strong, moist sharp acid taste 3scorching smell Low oxygen scorching smell acid taste like 4concentration formic acid method Aseptic method oxidized smell acidtaste like 4 formic acid Example of the fragrance of acid taste of 5present invention roast coffee coffee beans

As will be apparent from this table, the method according to the presentinvention has overcome all of the disadvantages of the prior artmethods.

INDUSTRIAL UTILITY

The present invention is applicable to manufacture of beverage of aroast material in a container by which a material of beverage such ascoffee beverage, cocoa beverage and roast barley beverage is roasted andbeverage is obtained by extraction or addition of water and then theobtained beverage is filled in a container which is then sealed.

1. Method for manufacturing beverage of a roast material in a containercharacterized in that processes from roasting of a material to fillingof beverage in a container and sealing of the container are conducted insterile atmosphere, extraction of the roast material or preparation of asuspension of the roast material is conducted with sterile water and, atleast in a part of said processes, sterile inert gas atmosphere is usedas the sterile atmosphere.
 2. Method for manufacturing beverage of aroast material in a container as defined in claim 1 wherein extractionof the roast material or preparation of a suspension of the roastmaterial is conducted with deoxidized sterile water.
 3. Method formanufacturing beverage of a roast material in a container as defined inclaim 1 or 2 wherein the beverage of a roast material is coffeebeverage.
 4. Method for manufacturing beverage of a roast material in acontainer as defined in claim 1 or 2 wherein the beverage of a roastmaterial is cocoa beverage.
 5. Method for manufacturing beverage of aroast material in a container as defined in claim 1 or 2 wherein thebeverage of a roast material is roast barley beverage.